The present invention relates to heat exchange devices and more particularly to reversible cycle heating-cooling devices employing a closed loop water circuit with means for tempering incoming outdoor ventilating air.
Reversible cycle heating-cooling systems having a closed loop water circulation circuit are known. The closed loop water circulation circuits are used to circulate water within a predetermined temperature range through the water-refrigerant contact coils in the reversible cycle heat-cooling units of the heating-cooling system in order to exchange heat with the refrigerant, thus, increasing the efficiency of the reversible cycle units and conserving energy. Prior art devices of this type are disclosed in U.S. Pat. No. 2,715,514 issued on Aug. 16, 1955 to W. S. Stair; U.S. Pat. No. 3,523,575 issued on Aug. 11, 1970 to J. B. Olivieri; and U.S. Pat. No. 3,630,271 issued on Dec. 28, 1971 to Herbert M. Brody.
Most buildings require a certain amount of make-up air or ventilation air to replace the air lost from the building due to the operation of equipment which functionally utilizes air, and to keep the air within the building fresh and suitable for humans. This make-up air or ventilation air is usually supplied from the outdoors through a ventilation system which ducts the ventilation air to various zones, such as rooms, into which the building is divided. In installations utilizing a reversible cycle heating and cooling system to temper the building air, the ventilation system is frequently completely separate and divorced from the heating-cooling system. The reversible cycle heating-cooling system is used to selectively heat or cool the air already in the building. In cold weather, the heating system must constantly heat the cold incoming ventilation air. This places an extra heating burden on the heating system over and above what it would be if no ventilation air were introduced into the building.
A solution to this problem is to pre-heat the incoming ventilation air before the ventilation system introduces it into the zones served by the reversible cycle heating system. The prior art method known to me is to use heating means such as an electric heater, hot water supplied heater, steam supplied heater and the like, disposed in the ventilation system. These prior art solutions all have two things in common. They all require the input of energy and they are separate and independent entities from the reversible cycle heating-cooling system.
Thus, a need exists for a device which is capable of pre-heating ventilation air without placing an extra burden on many or all of the reversible cycle heating-cooling units and which further, does not require as much additional energy.